Kotlin HTTP Call with AsyncTask example | Android

https://grokonez.com/android/kotlin-http-call-with-asynctask-example-android

Kotlin HTTP Call with AsyncTask example | Android

In this tutorial, we're gonna look at way to implement HTTP Call with AsyncTask to get data from Yahoo Weather API.

I. Technologies

• Android Studio 3
• Kotlin 1.1.51

  II. Overview

  1. Goal

  We will build an Android App that uses AsyncTask to implement asynchronous HTTP request to Yahoo Weather API:

2. HTTP Call with AsyncTask

2.1 AsyncTask

AsyncTask allows us to perform background operations, then publishs results on the UI thread without having to manipulate threads and/or handlers.

To work with AsyncTask, we must create its subclass, then override at least one method named doInBackground():

class GetWeatherAsyncTask : AsyncTask() {

    override fun onPreExecute() {
        // Before doInBackground
    }

    override fun doInBackground(vararg params: Params?): Progress {
        // ...
        publishProgress(progressResult)

        return result
    }

    override fun onProgressUpdate(vararg values: Progress?) {
       // use progressResult to do things such as updating UI...
    }

    override fun onPostExecute(result: Result?) {
        // Done: use result which is returned from doInBackground()
    }
}

2.2 HttpURLConnection

We use HttpURLConnection to work with HTTP-specific features.

• get a new HttpURLConnection by calling URL.openConnection()
• read the response from the stream returned by getInputStream() method (inputStream field in Kotlin)

More at:

https://grokonez.com/android/kotlin-http-call-with-asynctask-example-android

Kotlin HTTP Call with AsyncTask example | Android